TITLE:   GCN CIRCULAR
NUMBER:  17940
SUBJECT: V404 Cyg outburst (Swift trigger 643949 ): TSHAO optical observations
DATE:    15/06/17 14:52:17 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

E. Mazaeva (IKI), I. Reva (Fesenkov Astrophysical Institute), A. Volnova 
(IKI),  A. Pozanenko  (IKI) report on behalf of larger GRB follow-up 
collaboration:

We observed the  V404 Cyg outburst  detected by BAT/Swift (Barthelmy et 
al., GCN 17929), GBM/Fermi (Younes, GCN 17932; Jenke GCN 17935),  and 
Konus-Wind (Golenetskiiet al., GCN 17938) with Zeiss-1000 (East) 1-m 
telescope of Tien Shan Astronomical Observatory. Observations started on 
June, 15 (UT) 18:50:44 and continued on June 16.  We obtained several 
images in R-filter. The V404 Cyg optical outburst reported early (Gazeas 
  et al, GCN 17931; Oates GCN 17933) is clearly visible.  The V404 Cyg 
is overexposed in our initial images but can be recovered with more 
detailed analysis.

Preliminary light curve of the V404 Cyg can be found in

http://grb.rssi.ru/V404_Cyg/v404_20150615_lc.png

Photometry is based on following USNO-B1.0 stars

ID              R2
1238-0434779    13.52
1238-0434864    14.12